Retiring metric represents a Pipeline Slots fraction utilized by useful work, meaning the issued uOps that eventually get retired. Ideally, all Pipeline Slots would be attributed to the Retiring category. Retiring of 100% would indicate the maximum possible number of uOps retired per cycle has been achieved. Maximizing Retiring typically increases the Instruction-Per-Cycle metric. Note that a high Retiring value does not necessary mean no more room for performance improvement. For example, Microcode assists are categorized under Retiring. They hurt performance and can often be avoided.